With the richness of material life and the resulting increase in average life span, the number of hypertensive patients also increases in modern society. Obviously, it is very important to comprehend historic blood pressure values and blood pressure trends for daily prevention and treatment of hypertension. Therefore, a blood pressure value needs to be frequently measured.
However, the existing methods for measuring a blood pressure are mainly auscultation-based and oscillometry-based methods, both of which require one to wear an inflatable cuff and apply pressures on artery blood vessels to obtain blood pressure values, which cannot avoid discomfort caused by an increased pressure due to air inflation.
Currently, it has been put forward that there is a correlation between pulse wave transit time and a blood pressure during a period of time for a certain individual. Therefore, a corresponding blood pressure model may be established. However, this correlation varies with individuals. Thus, such a blood pressure model is only applicable to a particular individual but is not applicable to a group which comprises a large number of individuals.